1.Acute pain: two-thirds of the outpatients with emergency complaints or symptoms. 2.Chronic pain: >6 months delayed, relapsing, cured relapsing disease. (1) secondary pain: clear etiology such as cancer pain cervical spondylosis (2) primary pain: unknown etiology or neurological disorders caused by (3) functional pain: unknown etiology (4) organic pain: neurological disorders caused by (5) neurogenic pain: terminal type level 1; root stem type level 2. (6) Central pain: spinal type grade 3; brain type grade 4.